Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: 3/2/2007
Publication Date: 7/18/2007
Citation: Bongalhardo, D.C., Pelaez, J., Fulton, J., Saxena, S., Settar, P., O'Sullivan, N., Long, J.A. 2007. Rooster Semen Cryopreservation: Effect of Line Genetics and Male Age on Sperm Function. Joint Meeting of the ADSA, AMSA, ASAS and PSA. Journal of Poultry Science. 86(Suppl. 1):537. Interpretive Summary:
Technical Abstract: The fertility rates of cryopreserved poultry semen are highly variable and not reliable for use in commercial production or preservation of genetic stocks. Our objective was to evaluate the cryosurvival of semen from 8 pedigreed layer lines at the onset and end of production. Semen from 160 roosters (20/line) was frozen individually with 11% glycerol at 6 and 12 mths of age. Glycerol was removed from thawed semen by Accudenz gradient centrifugation. The viability of thawed sperm from each male was determined using SYBR/PI and flow cytometry. The fertilizing ability of thawed sperm was evaluated in vitro by assessing hydrolysis of the inner perivitelline layer. Hydrolysis data were grouped in 3 categories: <20 holes/mm2; 21-80 holes/mm2; and >81 holes holes/mm2. Viability data were compared among lines and between age groups by repeated measures ANOVA. For hydrolysis data, logistic regressions were calculated to predict the natural log of the odds for males within lines to be in 1 of the 3 categories. The percentage of live sperm increased (p<0.0001) with age (6 mths, 35.6 +/- 0.8; 12 mths, 41.4 +/- 0.7) and differed (p<0.0001) among lines, with 1 line consistently superior at both 6 and 12 mths. Hydrolyzing ability increased (p=0.0003) from 6 (54.5 +/- 6.1 holes/mm2) to 12 mths (96.7 +/- 9.4 holes/mm2) and differed among lines, with the odds of sperm hole category dependent upon line and age. Overall, viability was correlated with sperm hole number (r=0.24, p<0.0001) and category (r=0.25, p=0.0004); however, when the hydrolysis data were split by line and/or age, only 1 line consistently was correlated at both ages. These results demonstrate variability among pedigreed lines in withstanding glycerol-based semen cryopreservation and provide a model for delineating genotypic and phenotypic factors impacting sperm cryosurvival.